While people talk about affordable housing, they're not really in having it appear anywhere near them. Nobody wants to see their house value go down. Nobody wants to be inconvenienced. Few want more people underfoot, with those few who do being in urban developments. And they're obviously not worried about climate or commute time, as they legislate against the former and mandate in-office work against the latter.

Building homes where the land is cheap is probably the only alternative. But that's not where the jobs are. Building out the roads/sewer/power for such areas might also be an insurmountable problem.